Tokyo Electric Power Co. (TEPCO), which operates the plant, said
the damaged assemblies - 4.5 meter high racks with 50 to 70 rods
of highly irradiated used fuel - won’t be lifted from the plant’s
Reactor No. 4 when a large steel chamber, or cask, is employed to
move over 1,500 assemblies to safe storage, Reuters reports.

In an 11-page information sheet released in August, TEPCO said
one of the assemblies was even damaged as long ago as 1982, when
it was bent out of shape during a transfer.

In 2010, TEPCO said that another two spent fuel racks in the
reactor’s cooling pool possibly contained wire trapped in them.
Rods in the assemblies have small cracks and are leaking
low-level radioactive gases, TEPCO spokesman Yoshikazu Nagai told
Reuters on Thursday.

The damaged racks were first reported by a Fukushima area
newspaper on Wednesday, as TEPCO is preparing to decommission the
plant and remove the spent fuel assemblies from Reactor No. 4.

"The three fuel assemblies...cannot be transported by
cask," TEPCO spokeswoman Mayumi Yoshida told Reuters in an
email response on Thursday. "We are currently reviewing how to
transport these fuel assemblies to the common spent fuel
pool."

TEPCO is set to begin removing 400 tons of the hazardous spent
fuel, an unprecedented operation, beginning in mid-November.

The damaged assemblies will only make the job more difficult, and
could meddle with the year timeframe that TEPCO has set for
removal – which is already an ambitious plan to many.

TEPCO is in the process of decommissioning the entire six-reactor
Fukushima Daiichi plant after three reactors suffered core
meltdowns in March 2011. Moving the fuel assemblies in Reactor
No. 4 is the first priority, as their height above ground - 18
meters - is highly vulnerable to another earthquake.

Former US nuclear regulator Lake Barrett, who is advising TEPCO,
visited the plant Wednesday and endorsed the preparations for the
No. 4 assemblies.

"While removal of the fuel is usually a routine procedure in
operating a power plant, the damage to the reactor building has
made the job more complex," he said.

He added that he was "genuinely impressed by the thoroughness
of the effort and TEPCO's contingency planning."

The fuel assemblies will be lifted - all while submerged in water
to prevent overheating - from storage frames in the pool and
placed in the cask. Once the 90-ton cask is filled, it will be
lifted from the pool by crane, set on the ground, and transported
to a storage pool nearby.